The Tor Browser: layout/style/nsMediaFeatures.h@925c144e1f1f

     1 /* vim: set shiftwidth=4 tabstop=8 autoindent cindent expandtab: */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 /* the features that media queries can test */

     8 #ifndef nsMediaFeatures_h_

     9 #define nsMediaFeatures_h_

    11 #include "nsError.h"

    12 #include "nsCSSProps.h"

    14 class nsIAtom;

    15 class nsPresContext;

    16 class nsCSSValue;

    18 struct nsMediaFeature;

    19 typedef nsresult

    20 (* nsMediaFeatureValueGetter)(nsPresContext* aPresContext,

    21                               const nsMediaFeature* aFeature,

    22                               nsCSSValue& aResult);

    24 struct nsMediaFeature {

    25     nsIAtom **mName; // extra indirection to point to nsGkAtoms members

    27     enum RangeType { eMinMaxAllowed, eMinMaxNotAllowed };

    28     RangeType mRangeType;

    30     enum ValueType {

    31         // All value types allow eCSSUnit_Null to indicate that no value

    32         // was given (in addition to the types listed below).

    33         eLength,     // values are such that nsCSSValue::IsLengthUnit() is true

    34         eInteger,    // values are eCSSUnit_Integer

    35         eFloat,      // values are eCSSUnit_Number

    36         eBoolInteger,// values are eCSSUnit_Integer (0, -0, or 1 only)

    37         eIntRatio,   // values are eCSSUnit_Array of two eCSSUnit_Integer

    38         eResolution, // values are in eCSSUnit_Inch (for dpi),

    39                      //   eCSSUnit_Pixel (for dppx), or

    40                      //   eCSSUnit_Centimeter (for dpcm)

    41         eEnumerated, // values are eCSSUnit_Enumerated (uses keyword table)

    42         eIdent       // values are eCSSUnit_Ident

    43         // Note that a number of pieces of code (both for parsing and

    44         // for matching of valueless expressions) assume that all numeric

    45         // value types cannot be negative.  The parsing code also does

    46         // not allow zeros in eIntRatio types.

    47     };

    48     ValueType mValueType;

    50     union {

    51       // In static arrays, it's the first member that's initialized.  We

    52       // need that to be void* so we can initialize both other types.

    53       // This member should never be accessed by name.

    54       const void* mInitializer_;

    55       // If mValueType == eEnumerated:  const int32_t*: keyword table in

    56       //   the same format as the keyword tables in nsCSSProps.

    57       const nsCSSProps::KTableValue* mKeywordTable;

    58       // If mGetter == GetSystemMetric (which implies mValueType ==

    59       //   eBoolInteger): nsIAtom * const *, for the system metric.

    60       nsIAtom * const * mMetric;

    61     } mData;

    63     // A function that returns the current value for this feature for a

    64     // given presentation.  If it returns eCSSUnit_Null, the feature is

    65     // not present.

    66     nsMediaFeatureValueGetter mGetter;

    67 };

    69 class nsMediaFeatures {

    70 public:

    71     // Terminated with an entry whose mName is null.

    72     static const nsMediaFeature features[];

    73 };

    75 #endif /* !defined(nsMediaFeatures_h_) */

The Tor Browser / file revision